Transmyocardial and percutaneous myocardial revascularization: Current andfuture role in the treatment of coronary artery disease

Transmyocardial revascularization (TMR) is a neu treatment modality under e valuation in patients with severely symptomatic, diffuse coronary artery di sease, in whom the potential for medical or interventional management has b een exhausted. Preliminary clinical trials show improved ischemic symptoms within the first 3 months in about 70% of TMR-treated patients. The origina l proposed mechanism of surgical or catheter-based TMR (percutaneous myocar dial revascularization [PMR]) was that channels mediate direct blood flow b etween the left ventricular cavity and ischemic myocardium. However, severa l alternative explanations for the clinical success of TMR have recently be en suggested, including improved perfusion by angiogenesis, an anesthetic e ffect by nerve destruction, and a potential placebo effect. This article re views the clinical role of TMR/PMR, its possible pathophysiologic mechanism s, and its controversies, It provides an overview of the actual scientific and clinical status of TMR and details future directions.